Apparatus for forming sheet metal articles



June 19, 1945. s. K. WELLMAN 7 2,378,742

APPARATUS FOR FORMiNG SHEET METAL ARTICLES I Filed Feb. 2, 1942 5 Sheets-Shag}. 1

f; I 1 9 5 l7 56.2.

June 19, 1945. j s. K. WELLMAN 2,378,742

APPARATUS FOR FORMING SHEET METAL ARTICLES Filed Feb. 2, 1942 5 Sheets-Sheet 2 lAlwswrae:

5010 4 KWaL/ww Arraewsx June 19, 1945. s. K. WELLMAN 2,373,742

' APPARATUS on FORMING SHEET METAL ARTICLES Filed Feb; 2. 1942 5 Sheets-Sheet 3 w I 45 /35%/4 123 I2 54 UELKWEZIMA( Jar June 19, 1945. s. K. WELLMAN -2,378,742

" APPARATUS FOR FQRM'ING SHEET METAL ARTICLES Filed Feb. 2. 1942 s sheets-sheet 4 ATTORNEY June 19, 1945. WELLMAN 2,378,742

APPARATUS FOR FORMING SHEET METAL ARTICLES I I 7;; 56.. 20 w Angu/ar M68):

WVE/VTOR 179 750 'jAMuL A. WELLMA/V h 24 v i 4 I ATTOENEK Patented June 19, 1945 APPARATUS FOR FORMING SHEET METAL ARTICLES Samuel K. Wellman, Cleveland Heights, Ohio, assignor to The S. K. Wellman Company, Cleveland, Ohio, a corporation of Ohio Application February 2, 1942, Serial No. 429,200

2 Claims.

This invention relates to improved apparatus for forming sheet metal into arcuate or annular disk-like spacing members having corrugations extending between the inner and outer edges of the annulus so as to increase the effective orover-all thickness of the members, and relates more particularly to apparatus and methods for forming such members from straight metallic strip stock. J

It is an object of the invention to provide apparatus comprising a die mechanism capable of bending straight metallic strip stock so as to corrugate the strip transversely and form it into an armulus of the character in question without substantially drawing or stretching the metal.

A further object of the invention is to provide apparatus capable of operating automatically to form straight metallic strip stock into edgewisely-curved, transversely-corrugated arcuate or circular form without substantially stretching or drawing the sheet metal. Another object of the invention is to provide apparatus for forming relatively inextensible metallic strip stock into an annular or arcuate corrugated member having an eifective thickness at its outer periphery which is at least as great as the effective thickness at its inner periphery.

Another object of the. invention is to provide apparatus capable of operating more or less antomatically to form straight metal strip stock into edgewisely-curved, transversely-corrugated arcuate or circular forms, and in which the corrugating means form major corrugations and minor corrugations in alternating arrangements with the crests of the major corrugations aligned so as to define either a pair of spaced, parallel surfaces, or a'pair of spaced conical surfaces which diverge outwardly.

A further object of the invention is to provide apparatus such as last referred to in which the eorrugating means form minor corrugations having crests which decrease in height from the inner edge tothe outer edge of the formed memher and also form major corrugations having either uniform height from the inner edge to the outer edge of the formed member, or height which increases slightly from the inner edge to the outer edge, whereby a predetermined over-all or effective thickness of the member may be secured by simple bending operations without drawing or stretching the sheet metal. 1

Another object of the invention is to provide apparatus for forming straight metal strip stock arcuate or circular forms, and in which apparatus the corrugating meanscomprise a unitary circular series of spaced die elements adapted to engage the strip stock on one side thereof and a movable die element adapted to engage the strip stock-on the other side thereof, incomblnation with means for indexing the circularlseries of die elements so as to bring successive die elements and successive parts of the strip stock into position to be. engaged by the movable die element. 1 I

Another object of the invention is to provide improved indexing means for the die mechanism.

Another object of the invention is to provide apparatus capable of forming straight metal strip stock into edgewisely-curved, transverselycorrugated arcuate or circular forms, the apparatus being characterized by simple construction and reliable automatic operation.

With the foregoing objects and other more 0 less incidental or ancillary objects in view, the improved apparatus consists in certain forms, combinations and arrangements of parts, as hereinafter set forth and explained in connection with theaccompanying drawings and more pare ticularly defined in the appended claims.

In the drawings: v

Fig. 1 is a sideviewj with parts broken away,

of a clutch disk having a spacing member typical of the corrugated annular spacing members produced by the improved apparatus and methods of the invention.

Fig. 2 is a fragmentary view of the edge of the clutch disk shown in Fig. 1.

' Fig, 3 is a fragmentary sectional view taken on the line 3-3 of Fig. 1 and indicating the corrugated form of the annular spacing memher at the inner edge thereof.

Fig. 4 is a radial sectional view taken along I on the line 1-1 of Fig. 6, and shows the mainto edgewisely-curved, transversely-corrugated chine in its closed position;

Fig. 8 is a fragmentary sectional view with the section taken on line 8-8 of Figs. 5, 6 and? and showing' the parts when the machine is in its open position.

9 is a fragmentary vertical section on the line 9-9 of Figs. 6 and 7.

Fig. 10 is a vertical section on the line III-I of Fig. 6 and shows one form of ratcheting and indexing apparatus of suitable construction, with the various parts thereof in the positions'which they occupy when the machine is in its closed position. I

Fig. 11 is a fragmentary vertical section on line Ii-H of Fig. 7 showing the hold-down device.

Fig. 12 is a fragmentary vertical section on the line I2--I2 of Fig. 3.

Fig. 13 is a fragmentary sectional rear elevation with the section taken on the line I 3--I3 Fig. 17 isan elevational view of a blade suitable for use in the rotating die member of Fig. 6. Fig. 18 is a fragmentary vertical section taken similarly to Fig. '7, and showing the hold-down in the position which its blades occupy when the rotating die member of Figs. 6 and 7 has been advanced two spaces to. the left from the position shown in Fig. 7. I

Fig. 19 is a vertical sectional view of a modified device, the view corresponding to Fig. 7 above.

Fig. 20 is a side view showing the construction of one of the forming blades used in the device of Fig. 19.

Fig. 21 is a side view of another forming blade which is used in the device ofFig. 19.

Fig. 22 is a sectional view taken on the line 22-22 of Fig. 19 and shows the structure of the cams and their relation to the various other parts of the device at a time period slightly ahead of that in which the parts have the relationship shown in Fig. 19,

Fig. 23 is a diagrammatic sectional view illustrating a further modification. The View corresponds to the section taken on the line 23-23 ofFig.24. 1

Fig. 24 is a vertical sectional view taken along the line 24--24 of Fig. 23.

Corrugated sheet metal members such as have been referred to above have various applications or uses. An important use to which I have put spacing members of this character is in the construction of ventilated friction clutch disks,.and for the purpose of explaining my improved forming apparatus and methods I have shown in Figs. 1 to 5 of the drawings a clutch disk'having a corrugated spacer such as the forming apparatus illustrated in the drawings is adapted to produce.

Referring now to Figs. 1-5 inclusive, the friction disk assembly shown in the figures comprises a pair of backing or supporting disks I and 2 spaced apart axially at their centers by a spacing ring 3 and by the flange 4 of hub 5, the disks, flange and. spacing ring being secured together by means of rivets 5, 6. Friction facing layers 1, 1 are secured to the outer faces of the supportingdisks. A corrugated spacing member 8, such as my improved apparatus and methods are designed to produce,-is disposed between the disks in register with the facing layers, the. corrugafrom each other.

tions in the spacing member extending approximately radially across it and being of sufllcient length to support the friction facing layers throughout their full width. The form of the corrugations contributes to the floating action of the spacing member and will be described in detail below. The spacing member 8 is in the 7 form of a full ring or annulus, the ends of which are lapped as shown at 9 and spot-welded together. It is secured to the backing disk I in any suitable manner, but preferably by means of' spot-welds II], III located at a suflicient number of points to provide the desired strength and restraint. One set of such spot-welds I0 may serve 1 also to unite the lapped ends of meniber 8. Additional spot-welds II may also be provided to secure the spacing member 8 to the other supporting disk 2. Air inlet openings I2, I2 are provided in the assembly at appropriate locations to permit access of air to the inside of the assembly, thereby to permit forced-draft cooling or ventilation of the assembly when the disk is rotating.

Referring now to Figs. 2 and 3 which show the appearance of the outer and inner edges respectively of the assembly, it will be seen that the spacing member consists of a repeating series of corrugations, each series including a. major corrugation A, two intervening minor corrugations B, C, a second major corrugation D directed in the opposite direction with respect to major corrugation A, and another pair of intervening minor corrugations E and F. The series then repeats itself beginning with the major corrugation A. The major corrugations A and D of each series contact the supporting disks 2 and I, respectively, while the minor corrugations B, C, E and F are preferably of such effective height that they do not contact the supporting disks at any time, even when the friction disk is clamped in working engagement between the cooperating pressure plates of the clutch. It will be recognized that by reason of this construction, the backing disks and the facing layers are resiliently or floatingly supported upon the major corrugations and hence are cushioned over-their entire area, the

minor corrugations permitting variations in the over-all or effective thickness of the spacing member as the disks I and 2 move toward or away The minor corrugations may, of course, be designed so that their inner. ends come into contact with the supporting disks I and 2 when the clutch is in engagement, but the advantages of the floating-type of support are then largely lost.

In order to form corrugated segments or circles from straight strip metal, it is necessary to crowd or gather a given length of metal into a shorter space on one edge of the strip than on the other edge. This, of course, is due to the fact that one edge forms a circle of smaller diameter than the other. The minor corrugations in the corrugated spacing member shown in Figs. 1-5 permit the metal to be gathered at the inner edge to such an extent that straight strip stock may be formed into circular annuli having inner diameters on the order of an inch or so upward, and having wide ranges of annulus width. It will be noted from Figs. 2 and 3 that this is possible because, as mentioned above, the metal may be gathered in the minor corrugations B, C, E and F, the heights of these corrugations being adjusted to absorb whatever excess metal tion A and ending at the crest of major corrugation A, it will be seen that this series of corrugations begins at the inner edge (Fig. 3) at the crest marked a. and ends at thecrest marked a. Inasmuch as this series of. corrugations has the attributes of a geometrical wave, the circumferentialdistance (for a given radius) between major corrugations Aa and A'a' may conveniently be referred to as the wave-length of the series.

The same linear length of metal is included between the points A--A at the outer edge of the member as between the points -41 at the inner edge of the member, but the metal is crowded into a shorter space at the inner edge than at the. outer edge. As indicated above, this is accomplished by adjusting the heights of the minor corrugations, keeping their crests, of course, below the crests of the major corrugations, and preferably by keeping them below the latter crests by an amount appreciably greater than the cushion deflection which is desired in the spacing member.

It will be noted that the crests of the minor corrugations are not parallel to the crests of the major corrugations, the crest of minor corrugation Ee in Fig. 4, for example, being inclined in one direction with respect to the crests of the major corrugations, while the crest of minor corrugation Ff of Fig. is inclined in the opposite direction. This is because the height of the minor corrugations at the inner edge of the annulus needs to be greater than the height of the same minor corrugations at the outer edge in order to absorb the metal properly. It will consequently be appreciated that if the height of the minor corrugations with respect to that of the major corrugations is adjusted to provide the desired deflection of the spacing member at the inner edge, the heights of the minor corrugations at their outer ends will automatically be smaller, the limitingcondition being that in which the minor corrugationsdisappear at the outer edge leaving astraight web extending from one major corrugation to the next. This extreme condition should generally be avoided since it impairs the resilience of the spacing member at the outer edge.

It will be understood from what has been said above that the linear length of metal included in a wave-length of each undulationin the above described floating-type spacing member may be varied within limits which permit various amounts of cushion effect;

As has been indicated, the corrugated spring member 8 shown in Figs. 1 to 5 typifies the sort of arcuate members which my improved apparatus and methods are'designed to produce. The machine shown in Figs. 6-18, inclusive, illustrates one form of machine which may be used for this purpose. Referring now to Figs. 6-10,

inclusive, it will be seen that the machine consists of an assembly which is designed to be installed in a punch press for actuation thereby. The machine consists of a base 20 adapted to be secured fixedly as at 2| and 22 to the bed of a suitable punch press the slider or ram of which is indicated at 23 in Figs. 7 and 8. The base is provided with two upstanding guide pins 24 and 25 rigidly secured thereto to act as guides for a movable top platen 26, which is connected to slider 23 of the punch press so as to be reciprocated in an up and down manner parallel to the vertical axes of guide pins 24 and 25. As will be seen more clearly in Fig. 6, the fixed base 20 carries 'a rotating die structure G which is dis posed flatwise thereupon and constrained thereon for rotary motion about a central fixed hub 28. The rotating die consists of a base disk 29 having a central recessed portion 30 whose thickness is about the same as the height of hub-28 above the top surface of base 20. A washer 3| is secured to the top end of the hub concentrically therewith so as to overhang a portion of the said recessed portion 30. It will thus be-understood that the washer is effective in holding the disk 29 in contact with the upper surface of base 20 while permitting the disk to rotate freely about the hub 28. The washer 3| may be secured to the hub in any'suitable manner, as by means of screws 32,32. The unrecessed face portion of the disk 29 i provided with a circular series of radially directed slots 33 extending a. convenient depth into the disk. The number of slots is optional, depending largely on the size of the annulus which is to be formed, but the number of slots which is provided should preferably be a multiple of three when forming a spacing member corresponding to member 8 of Figs. 1-5. Each of these slots carries a blade 34 disposed therein on edge and projecting from the exposed top surface of the die base 29. The upper edgeof each blade provides a, rectilinear forming surface over which the strip metal may be bent, as will be understood subsequently. Each of the blades 34 is provided with a triangular portion which projects from the inner end thereof, the function of which is to aid in securing the blade in the die assembly. A typicalblade is illustrated in Fig. 17 and the triangular portion is shown at 35. The blades are disposed in said slots with the triangular portions at the inner ends of the slots, as shown in Fig. 8. A beveled locking ring 36 is disposed between the inner ends of the blades and the washer 3|, and is secured as by screws 31, 31 to disk 29 so that its beveled edge portion 38 is brought to bear against the triangular projecting portions 35, of the said blades. As will be understood through reference to Fig. 8, this construction prevents the blades from being pulled out of the rotating die. The rotating'die is completedv by means of a. peripheral toothed ring 39 provided with a multitude of teeth 40, 40, the number of teeth therein corresponding to the number of blades in the rotating die member. A slot 4| of suitable width separates adjacent teeth of said toothed ring, this slot extending radially across the ring and downwardly to a level which is at least slightly below the plane of the upper surface of disk 29. The toothed rin is secured to the periphery ofthe disk 29 by means of a plurality of circumferentially spaced screws 39a, but is positioned on the periphery of the disk 29 so that each slot 4| is midway between a pair of blades 34, 34. Thus the slots lie at the extremity of each of the forming cavities 42 of the die member and each is centered with respect to its corresponding cavity. This construction permits a vertically movable blade (described hereafter) to be forced downwardly on edge into each cavity while being aligned with the cavity by one of the radial slots 4H of the toothed ring.

As will be understood more fully hereafter, the

blades of the rotating die member are arranged to form a repeating sequence of high andlow forming edges with intermediate forming cavities 42..

Such a sequence is required in forming the corrugations of the spacing member 8 of Figs. 1-5 inclusive. Thus the blades are arranged in sets so that there is one high or major blade followed support by means of screws 41. 41.

by two low or minor bladm, the latter being fol- By using a number of blades which is a multiple of three, the successive sets of blades cooperate to provide a continuous forming die in which the repeating sequence is endless. The major blades as shown have their forming edges parallel to the surface of the die base 28 but the formingedges of the minor blades are inclined. Considering a median plane of the. major female die blades disposed midway between the surface of the base 28 and the'forming edges of the said blades, the forming edges of the minor blades are above said plane and incline it.

The fixed base 28 also carries an inclined guiding assembly H adapted to guide the strip stock in a' flatwise position tangentially into the rotating die member. This guiding assembly consists of a support 43 secured to base 28 by means of suitable screws 44. On the upper surface of inward and upward away fromacreage the support is secured an elongated frame 45 having a shallow groove 48 formed in the top face thereof. The said frame is secured to the attachment is mounted upon the frame so that it may be moved back and forth in the groove 45 thereof for suitable adjustment of its radial position relative to the center of the rotating die member. The guide attachment consists of a beveled bar 48 having slots 49 at itsopposite ends,

and a pair of guide plates 58 and 5| secured to each other and to said bar in such manner as to form a thin opening through which the strip stock may be fed in flatwise position. The guiding attachment is secured to frame 45- by means of screws 52, 52 positioned in the said slots 49 at opposite ends of the bar 48.

. The fixed base also carries a stationary holddown J, the function of which is to hold the corrugated stock in mesh with the forming edges and forming cavities of the rotating die member. This hold-down consists of a segmental plate 54 having three studs 55 secured thereto to lie on 'a' radius of the segment. This construction will be understood more fully through reference to Fig. 9. The three studs extend upwardly throughopenings in a frame member 56 andcarry nuts 51,51 on their upper extremities. The frame member is secured to a support 58 and to the base 28 by means of screws 59, 59. A spring 68 is interposed between said segmental plate 54 and said frame member 56 so as to resiliently impel said segmental plate downwardly with respect'to the fixed frame member. It will be understood that this construction permits the segmental plate to be retained in position above the rotating die member, or to be forced into contact with the top edges of the high blades thereof under yielding pressure. The functions of the hold-down will be explained subsequently in connection with the operation of the device. It will be further understood, however, that the fixed hold-down must necessarily be positioned so that its segmental plate may be effective A guiding 84 and lever 8|. The plunger is preventedfrom as shown in Fig. 6.

whole guide assembly is positioned on the b'ase 28 so that this-slot is in radial alignment with the center of rotation of the rotating die member,

A brake assembly L is also secured tothe base 28 so as to restrain the die member from rotating too freely. This brake assembly consists of a hinged arm 85 pivoted at one end albout-a screw 61 so as to be rotatableabout said screw toward and away from the periphery of the rotating die member. The other end of the arm 86 carries a block 68 of suitable friction material, preferably of the sintered metal -variety. The'armand its attached friction'material is resiliently pressed toward the rotating die member by means of a spring 69. Pressure is applied to thespring by means of a screw 18. A cup H is attached to the end of the screw to provide a seat for the spring. The screw 18 is threaded into a trunnion block 12, the latter being secured to the base 28 by means of screws I3. The position of the screw 18 relative to trunnion block I2 may be fixed by means of a lock-nut l4 threaded on said screw 18. The function and operation of this assembly is self evident.

A ratcheting and indexing mechanism M is also secured to the base in a position which permits a ratchet thereof to engage .with the teeth of toothed ring 39. .This ratcheting and indexing mechanism is shown most fully in Fig. 10 to which reference is now made. It will be seen to consist of a frame 15 secured to the base 28 by means of screws 18. A rocker plate 11 is secured to the frame by means of pivot screw.l8, and at one of its ends it is pivotally attached to a pawl 19 which is adapted to engage the upper ends of the teeth 48 of the toothedring-il of the rotat- The rocker plate 11 is also provided with a projecting portion 83 through which motivating energy is applied to. theiratcheting' and indexing mechanism. The pivoted lever 8| carries an adjusting screw 84' at its; remote extremity, and the frame 15 carries a cylinder and plunger assembly directly beneath said adjusting screw. The cylinder isshown at 85 and is secured to the frame by means of screws 86, 85' (Fig. 6). Plunger 81 is disposed within the cylinder and is adapted to movev vertically up and down'therein inresponse' to pressure applied to it through adjusting screw rotating in the cylinder'by means ofaltransverse pin 88, the outer ends of which are guided by slots 89, 89 in the walls of said cylinder 85; A coil I spring so is interposed between the plunger and in holding the. corrugated strip stock firmly in mesh with the rotating die member, without interfering with the action of the forming blade, or with the movable hold-downs described hereafter;

A rear guide assembly K for the forming blade 8| is secured to base 28 a short distance be-' yond the periphery of the rotating die member. This guide assembly is best shown in Fig.. 13, where it will be seen to consist of a U-shaped thebottom of the cylinder and serves to retract the plunger when the lever 8| is not pressing it downwardly. The bottom endof the plunger is provided with a V-shaped point which is adapted to extend downwardly into the slot between adjacent teeth of the toothed ring 88 until the edges of the point engage the walls of adjacent teeth 48, 48. It will be understood that .the purpose of the ratcheting and indexing mechanism is to advance the rotating die one tooth at a time and then to bring the die'mem'ber to'rest so that the slots between adjacent teeth of the toothed ring are brought consecutively into'exact radial alignment with the slot 65 of the rear guiding assembly K. The operation of the mechanism will be explained hereafter in more detail.

As indicated previously, a reciprocating top platen 25 is guided on the two guide pins 24 and 25 of base 20 so as to be movable up and down or toward and away from the rotating die member. This reciprocating platen carries a forming blade 9| which, as shown in Fig. 6, extends radially across the full annular width of the rotating die member and is guided into position on die.

member G by the slot 05 of rear guiding assembly K and by a front guide 53. As will be understood subsequently, this blade 'has the function of bending the strip stock over the top edges of the fixed blades 34, 34 of the rotating die member and of bending the stock around its lower edge. In order to be effective in forming corrugations of the proper configuration, the blade is pivoted near its inner end so as to be rotatable in a vertical radial plane relative to the rotating die structure G. The structure of the blade mounting assembly N is shown most clearly in Figs. 8 and 12. The assembly includes an angle iron frame 92 secured to the under side of top platen 26 by means of screws 93. A pivot block94 is secured to the depending leg 95 of angle 92 by means of screws 96.

. This pivot block is recessed as at 91 to receive short leg of the L-s'hap'ed frame I00 retained fiatwise against a face of pivot block 94 by means of pivot screw 90. Theblade is guided near its rear end by means of the guide assembly P shown in Fig. 13. The said guide assembly P (Fig. 13)

consists of a pair of plates I02 and I03 fastened- The . washer.

Another washer H5 is disposed on the threaded screw portion I09 adjacent the other face of ratchet wheel H2 and is pressed thereagainst by means of a spring IIB suitably loaded in compression by means of a nut Ill threadably engaged with the threaded screw portion I09. It will be understood that the spring is effective in clamping the cam and ratchet wheel assembly against the opposite faces of plate IIO. By adjusting the spring pressure, the frictional force between the cam assembly and the plate H0 ma be adjusted and thus utilized to prevent the cam from rotating too freely. Washer II3 may be composed of sintered metal friction material if desired, so as to introduce more friction than could be obtained from an ordinary metal Referring now to Figs. 8 and 15, it will be seen that the cam I06 is provided with six distinct bearing surfaces, four of them being arranged in two pairs disposed on opposite sides of the cam and separated by curved end portions. Thefour flat faces of the cam are all tangent to the same circle while the curved sections are portions of a circle of greater diameter. Accordingly, it will be seen that the cam provides a sequence of posi-' tions by which it is capable of depressing the blade 9| to a maximum depth in one position, and then of permitting the blade to be retracted to a lesser depth in two succeeding positions. As the cam rotates further, it repeats this cycle of positions, thereby p oviding two complete cycles of the same tri-position sequence. The ratchet wheel '"carries six teeth equally spaced circumferentially and positioned relative to the cam so that rotation of the ratchet wheel may be effected in sixty degree intervals to bring the six faces of the cam consecutively into contact with thetop edge of blade 9|.

The mounting and construction of the blade 9| and its cam actuating devices are such that the together in spaced relation to provide a channel of the proper width in which blade 9| may move in edgewise directions. The guide assembly P is secured to dependingleg 95 of angle 92 by means I of screws I04.. From this construction, it will be seen that the blade is free to undergo limited rotation in a vertical plane about pivot screw 98 as its center of rotation while, at the same time, being rigidly connected to the reciprocating top platen 26. w

A coil spring, I05 'isconnected between the angle 92 and the blade 9| to bias the blade against the face of a cam I06, as shown in Figs. 8 and 15. The cam is rotatable about -a horizontal axis and is of such configuration as to cause the inclinaand rear guide assembly P. The construction or; I

the cam assembly Q .is shown most clearly in Fig. '1 where it will be seen that the cam. I08 forms the head of a spindle having a-fl zst" lindgical portion I01 followed by a square shoul' ered portion I08, and then by a cylindrical threaded forming edge of the blade, when it is inserted between a major blade and a minor blade of the female die, is .below the median plane of themajor blades of the female die and inclines inward and downward away from said plane.

Rotation of the ratchet wheel and cam as 5 sembly Q is effected by means of the reciprocating motion imparted to the top platen by the punch press. For this purpose a bell crank H8 is pivoted on pivot pin- I I9 relative to the depending leg 95 of angle 92. One leg of the crank extends outwardly beyond the end of angle 92 and is provided with a striking pin I20, as shown in Figs. 8 and 14. The other leg of the crank is tached a block I30 as by means of screw I3I.

The block I30 is positioned on the upright portion so that striking pin I20 will be brought into engagement with it during at least a part of the portion I09. The cylindrical portion I01 is-"journaled in a'supporting plate IIO which is flatwise against depending leg 95 of angle 92 by bythe square shouldered portion l00 of the spindle. A washer H3 is interposed between the ratchet wheel In -and a bearing boss M4 on plate upward motion of top platen 25. When the striking pin has thus been brought into engagement, further motion of the platen upwardly causes the bell crank to be moved in a counterclockwise,

direction about pivot II9. This, in turn, causes the hook I23 to be pulled away from stop pin I26 and thereby to engage a. tooth of ratchet wheel I I2 and cause the ratchet wheel and as- I25 serves to bias the hook laterally sociated cam to be rotated through about sixty platen. v r

The reciprocating motion of the top platen is pieces I31, I31.

degrees of angle. As the top platen moves downwardly, this cycle of motions is reversed and hook I23 slides back over the adjacent tooth of ratchet wheel H2 and ultimately comes to rest against stop pin I26. It will thus be seen that theflup and down motion-of the top platen is utilized to effect. rotation. of the cam in synchronism with the reciprocating motion of the also utilized to actuate the ratchet and indexing mechanism M. Asshow'n in'Figs. 6 and 10, the

top platen carries a depending adjustable .hook

I32 adapted'to come into engagement with the v projectingportion I33 of rocket plate 11 during at least a part of the upward motion'of the platen. The hook I32 is secured to an angle frame I33 by means of screw I34, the angle being in turn secured to platen 26 by means of screws tion it must be adjusted and properly timed.

This involves the following items:

Adjustment of the displacement of the punch press The displacement or stroke of the punch press which actuates the device must be chosen so that when the press is moved to its extreme lowermost position (the'closed position), the forming blade 9| will be spaced above the top surface of disk 29. by any-suitable amount equal to or greater than thethickness of the strip stock whichis being formed. The displacement must also be chosen so that when the press is moved to its uppermost or open position, the forming blade 9I and hold-down blades I44 and I45 will be raised well above the tops of the teeth 40 of I "the toothed ring 39. When a press of suitable I39." It will be understood that this construction causes the ratcheting and indexing mechanism to move in synchronism with eating movement of the platen.

For the puropse of retaining the formed or corrugated strip stock in contact with the rotating die member while succeeding portions of the strip stock are formed, a resilient hold-downR is provided. Thishold-down is shown in Figs. 7, 11 and 18, and will be seen to consist of a box-like frame composed of side plates I36, I36, and end The frame is secured to top platen 20 by means of screws I38. The opposite end pieces I31, I31 of the frame are provided I with inwardly directed shoulders I39, I39. With- ,in the cavity 01' the frame are positioned two blade carriers I40 and MI, both of which carry outwardly directed shoulders or stops I42, I42 adapted to engage shoulders I39, I39 of the frame and thereby prevent the carriers from dropping out of the'plane. The blade carriers are mounted against sponge rubber pads I43 so as to be resiliently pressed downwardly, but at the same time to be free to move independently of each other. The blade carriers I40 and HI support holddown blades I44 and I45 respectively. The blades of the hold-down extend radially across the annular portion of the rotating die section G, as shown in Fig. 6, and are dimensioned in length so as to be guided by adjacent slots 4|, H of the toothed ring 39. The inner ends of the holddown blades are loosely guided by means of a uide member I 49 which is secured to washer 3| oi' the fixed base. As shown is Fig. 7, theholddown blades I44 and I45 are adapted to contact the corrugated strip in the troughs of adjacent corrugations thereof, and thereby to hold the corrugated strip in mesh with the blades and cavities used in forming the various corrugations. The corrugated strip is thereby held firmly in position on the rotating die member while the forming blade 9| is bending a succeeding unformed portion of the strip stock around the top the reciprostroke has been selected, the adjustment of the position of the forming edge at the bottom of a downward stroke may be made by means of a threaded member which forms a part of the connecting rod of most presses. By rotating the member in a-suitable direction, the length of the connecting rod may be increased or decreased, with the result that the forming blade may be brought to a desired distance away from the surface of the die member.

Adjustment of the pivot point and cam'rel ative to the forming blade sary that the inclination oi the i'orrning blade 9I be established at the proper value prior to completing each of its strokes. The desired inclination may-be obtained by shifting the pivot point 98 along leg of angle 92 so as to'move it towardv or away from the center of the rotating die member G, and meanwhile raising or lowering the plate 0 and its associated cam mechanism Q. Itvwill be understood that the inclination of the blade so far as its shallow strokes are concerned, can beincreased by moving the pivot point nearer to the cam I00, and that insofar as the deep corrugations are concerned, the inclination of theblade relative to the surface of disk 29 may be adjusted by moving the plate II 0 and cam I06 up or down on the angle 92. It will also be recognized that further adjustment of both can be provided by using earns 01 different sizes. With a cam of given size, however, suitable adiustment can usually be round by moving the pivot point 99 and the plate H0 in the manner indicated above.

Timing of the deep and shallow strokes in corvrespondence with the high and low blades of the rotating die section tering the cavities which lie between a high or major blade anda low or minor blade of the ratating die member. In order that these positional requirements may be obtained, it is necessary that the cam I09 be timed properly with relation to' the rotating die member. This timing may be accomplished by rotating cam I06 until i one of the curved end portions has been brought into contact with the top edge' of the forming blade 9|. With the punch press in its open position, the rotating die member should then be rotated so as to bring two adjacent minor blades thereof into flanking positions on opposite sides of the forming blade 9| so that when the punch press is actuated to move the assembly to its closed position, the forming blade will be depressed into the cavity which lies between the said minor blades.

Timing of the cam relative to the upward motion of the platen In order that cam I06 may be rotated at the proper point of time in the cycle of operations, it

' is necessary that the block I39 be properly positioned on bracket I29. To do this, thecam I06 3 should be rotated until one of its curved end poring block I39'should then be fastened to the upright bracket 29 so that its bottom face is in contact with the striking pin I 29 of bell crank I I8. The platen ofthe punch press should then be raised to the uppermost position (open position). When it has been brought to this position, the hook I23 should have been effective in rotating the ratchet wheel II2-and cam I06 through an angle of about 60. If this is done, the adjustment is correct. If, however, the cam is rotated through an angle much greater than 60, then the striking block I39 shouldbe raised upwardly .on bracket I29 to reduce the angular rotation to the desired value of 60.

Timing the advancing and indexing mechanism relative to the upward motion of the platen It will be recognized that pawl 19 should not begin tofadvance the rotating die member until after forming blade 9| has been raised high enough to clear the tops of teeth 40 of the toothed ring 39. Furthermore, the pawl should have been effective in completing the advancing action by the time the platen 26 has beenraised to its uppermost position. An adjustment of member I32 can be found which will make the pawl perform these functions at the proper time intervals. To find the proper adjustment; cam I98 should be rotated until one of its-curved end portions has been brought into contact with the top edge of forming blade 9I. The punch-press should then be actuated so as to raise the platen far enough to lift the bottom edge of the forming blade slightly above the tops of the teeth 49 -of toothed ring 39. Member I32 should then be fastened to the platen by means of screw I34 so that its hooked end portion bears against the bottom face of the projecting portion on rocker,

plate 11. With the member so fastened, the platen should'then be raised to its uppermost position to make certain that pawl 19 does not move too far as a result of this further upward motion. If its lateral motion is found to be too great, with the re it that the rotating die mem-, her is rotated a distance of more than one tooth, then member I32 should be loweredrelative to 1 ing the strip stock I41 through the device.

' since it is needed for this purpose.

(open) position while observing pawl 19 and plunger 81. correct, then the pawl 19 will advance the rotating die member only one tooth at a time, and plunger 91 will move downwardly at such a rate that it will not strike the top of any tooth of the toothed ring 39 in its descent. Furthermore, when the platen has reached its uppermost position, the pawl should have reached the extremity of its forward stroke while .the plunger 81 should have come to rest with the faces of its V-shaped point in light but firm engagement with the adjacent walls of adjacent teeth 40 of the ring 39. Screw 84 should be adjusted until such an adjustment of the plunger 81 has been obtained.

After the preceding adjustments have been made as indicated, the next step which is involved to place the device in operation is that of thread- Th s threading step is essentially a procedure which must be done by the operator before the machine duced into the rotating die member by sliding it longitudinally through the opening between plates 50 and 5| of guide H. The stock is advanced into the die member far enough so that its leading edge is slightly beyond the forming blade 9|; The punch press may then be set in motion so as tocomplete only "one revolution. This motion of the punch press will first depress the forming blade, thereby bending the strip to form a corrugation, and thereafter will again raise the platen to its open position. The cormgation thus formed is apt to be of imperfect configuration because of the fact that the stock had not been suitably restrained while it was being bent. However, the corrugation should not be severed from the strip or discarded until after the stock has been threaded through the machine To this end, the operator should hold it in the cavity in which it was formed while the upward motion of the platen acts to advance the rotating die member one space to the left. When this is done, the rotationof the die member is eiifective in pulling additional strip stock beneath the'forming blade. The press may then be set in motion to form a second corrugation. On this next downward stroke of the punch press, the movable hold-down blade I should be effective in holdingthe stock platen 26 until an adjustment isfound which causes the pawl to move forward and back the required distance. The .adjustment should then be checked again by moving the platen from its lowermost (closed) position to its uppermost in place while the forming blade forms the susceeding corrugation. It will be noted that when it is so held by the hold-down blade I, the strip is effectively anchored relative to the blades of the die member. As a result,- the forming blade assumes substantially its complete function n I though it is of such temper and composition that it has substantially no elongation. After the second corrugation has been formed, the operator must hold both the first and second corrugations If the adjustment of member I32 is in their respective cavities while the rotating die member is advanced to bring the third cavity be neath the forming blade. n the'third down- 1 ward stroke of the punch press, both of the movable hold-down blades land I45 contact the corrugatedstock and hold it in position while the third corrugation is being formed. Upon completion of the third corrugation, the operator must. again hold the corrugations in the rotating die member as the latter is being advanced.-

Ultimately, however, a crest corrugationwhich has been formed around the top edge of one of the major blades of the die member will be in a position to pass beneath plate 54 of the fixed hold-down. After such a corrugation has been brought under this plate, further attention by the operator is unnecessary since thereafter the cor.-

ated and arcuately-curved member formed from the straight strip stock passes out from under'the holdedownplate'fl, it .graduallysprings upward out-of thedieldepressions and falls over the sides} of the die-to accumulate in spiral form on the rugated stock will be held in position automatically as the rotating" die member is advanced.

The threading'ope'ration is thereupon complete.

Assuming now that the strip stock has-been threaqzled into the machine and that the machine has been adjusted and timed for automatic operation, as describedabove, the action of the various parts maybe traced. It will be understood gating such stock in a continuous manner so as to toothed ring 38, the indexing mechanism advances the rotating die section one forming cavity to'the left, and the inclination ofthe forming *blade is meanwhileadjusted to prepare it for the next downward stroke of the platen.

In the operation of the machine, as the corru-i floor'or otherfsu'pport at the side of the machine A stripping uide s-may be provided to facilitate I this removal or stripping of the corrugated material from the rotary die member.

From the foregoing description, it will be ap-,

parent that the machine is capable of handling strip stock from long coils or rolls, and ofcorruform continuous spirals of .corrugated material. The latter may subsequently be cut into portions of the proper length for use in the clutch assembly of Figs. '1 through 5. In view of this feature that due to the function of the hold-down plate 54, the advancing die member pulls a succeeding portion of unformed strip stock beneath the forming blade as the rotating die member is" advanced after completion of each corrugation.

The hold-down plate 54 anchors theleading end of the stock to permit the die member to do this.- It will also be understood that as-the forming the stock downwardly into the cavity while pulling enough additional strip stockin also to form a corrugation of the desired configuration. Furthermore, it will be understood that as the platen moves upwardly upon completion of each corrugation, the movable hold-down blades I and H5, and the forming blade 9|, areretracted and. are carried upwardly to a height which causes.

their lower edges to rise above the top of the teeth of the toothed ring 39. When this has been accomplished, the adjustment of hook I32 andof the fact that the annulus is formed fromstripstock rather than from circumscribing squaresoffsheet metal, or otherwise, there is practically no waste involved, all of the strip stock being. consumed in forming corrugated stock which may be used without waste in making jointed annular spacing members for the clutch plate assembly. From what has been said previously, a will also be recognized that the blade is then depressed into each cavity, it bends I machine may handle strip stock of any appropriate composition and temper. vWhile it is designed especially for use with relatively inextenformed except by bending operations. Consein Fig. 10 should be such that it comes into contact with portion 83 of rocker plate 11. Further upward motion of the platen then sets the advancing and indexing mechanism of Fig. 10 into operation, pawl 19 moving the die member to the left or in acounter-clockwise direction, and lever 8| causing plunger 81 to move downwardly toward the toothed ring 39. By the time the platen has reached its uppermost position, pawl 19 is in its extreme position toward the left, and the V- shaped pointv offplunger 8'! has been brought to rest in mesh with the walls of a pair of adjacent teeth. Meanwhile the apparatus of Fig. 8 has also been motivated by the upward motion of the platen. explained previously, during the upward motionof the platen, striking pin I20 of bell crank I it? isbrought into contact with the adjustable stop block I30, carried by bracket I29. Further upward motion of the platen thereafter causes the hook link J23 to engage a tooth of a ratchet wheel H2, causing the latter to rotate through approximately 60 of angle. This rotation advances the cam 16 of Fig. 15 to its nextsucceeding position. therebyestablishing the inclination of forming blade 9| whichis needed in forming the next corrugation. In summary, therefore, it will be recognized that after the platen has been raised upwardly by the punch press to a-point where the forming blade and hold-down blades have cleared the teeth of the quently, there is no mechanical deformation involved beyond that of simple bending, and the resultant corrugated stock is only slightly works hardened.

It will be appreciated that any given die structure G may be used to form annuli of a limited range of diameters'if its blades '34 are wider than the strip stock which is to be corrugated. If a wider range of diameters is needed, it is usually preferable to provide several machines with rotating die members of different sizes, rather than to attempt to design one rotating die member capable'of accommodating all of the different annulus diameters. This is the result of structural limitations imposed on the design by mechanical considerations, rather than by any failure of the basic principles to permit such a die member to beprovided.

Those skilled in the art will appreciate that thebasic principles of the device of Figs. 6-18 inclusive may be embodied in various machines which depart in mechanical structure and arrangement from the machine thus far described and explained. Two of such alternative constructions are illustrated in Figs. 19-24.

One alternative construction is illustrated in Figs. 19-22 inclusive, vIn this device a rotating die member I50 of the type shown in Figs. 6 -18 inclusive is employed and is mounted for rotation about a. center on a fixed base l5|. The construction of the device is as shown in Figs. 6-18 so far as the rotating die member and fixed base are concerned. A fixed hold-down I52 is provided and may have the construction shown in Figs. '1 and 9 above. The movable forming blade SI of Figs. 6, 'I and 8 has been replaced in the modification here illustrated. In the device of Fig. 19, a stationary box-like frame I53 is provided above the'rotating die member and carries five blades I54, I55, I56, I51 and I58, each of which is mounted therein for constrained motion toward and away from the die member I50. Blades I54 and I55 have the same functions as hold-down blades I44 and I45 01 Figs. 6-18 inclusive. Blades I56, I51 and I58 are combined. in their individual functions so as to take the place of the single movable forming blade 9| supra. As will be understood from the preceding discussion of Figs. 6-18 inclusive, the forming blade 9| assumed three positions in its complete cycle of operations, I these positions being imparted to it by the various positions assumed by cam I06. In the device of Fig. 19, each of the blades I56, I51 and I58 has its respective forming edge I56, I51, I58, shaped properly so that each one makes only a Single corrugation of predetermined configuration. Thus blades I56 and I58 are beveled as shown in Fig. 21, the bevel corresponding to the inclination which would be assumed by blade 9| at the two shallow or inclined positions of the latter if it were forming the same annulus. Blade I51 has a forming edge which is substantially parallel to the top surface of the rotating die member. It thus has the construction shown in Fig. 20 and will be recognized to duplicate the position assumed by blade 9| when the cam I06 has been rotated to bring either of its curved end portions into contact with the top edge of the blade. As indicated above, blades I54 and I55 serve as hold-down blades. Blade I54 is similar in construction to blade I51 and is shaped substantially as shown'in Fig. 20. Blade I55 corresponds to blades I56 and I58 and is similar to the blade shown in Fig. 21. The five blades carried within frame I53 may be actuated by any suitable mechanism which will depress them in the proper consecutive sequence and at the proper points of time. A rotary cam assembly I59 is shown in Fig, 19 and it carries 5 cams I60, I6I, I62, I63 and I64 which actuate the blades in the desired sequence and with the proper timing. The contour of each of the various cams is shown in Fig. 22.

The operation of the device is as follows: As will be noted, the die member I50 is shown with the strip stock I65 threaded therethrough and in a position such that a major trough corrugation is directly below blade I54 and with a minor trough corrugation below blade I55. The strip stool; to the right of fixed blade I66 is in position to be corrugated. .In order to corrugate this uniormed strip-stock, the device is operated by depressing blades I54 and I55 sufliciently to bring their forming edges into firm contact with the troughs of the corrugations which are directly beneath them. As will be understood, when these blades have been so depressed, they anchor the corrugated stock firmly in contact with the rotating die member. Blade I56 may then be depressed to the position shown in the dotted lines, thus forming the minor corrugation I61 by drawing additional strip stock under its forming edge as it moves downwardly to its ultimate position. As soon as blade I56 has been brought to rest in its ultimate position, or slightly before, blade I51 may begi'n its downward descent. In any event, this blade should not contact the uniormed strip stock appreciably before blade I56 has come to rest at its lowermost position. With this sequence of events, blade I51 pulls additional strip stock into the cavity between blades I68 and I69, and when it has been depressed to its ultimate position it will have completed the formation of the major corrugation I10. When this has occurred, or slightly before, blade I58 may begin its descent. When this latter blade has finally come to rest in its ultimate position, it will have pulled strip stock into the cavity between the blades Iris and III to form the final minor corrugation I12 of the series. It will be recognized that at this point of time all live blades are in contact with the strip stock. The next step in operating the device is to raise all five blades upwardly far enough to permit the rotating die member I50 to be indexed beneath them.- This is accomplished by rurther rotation of the cam'assembly, as will be understood from Fig. 22, to permit the blades to be retracted into frame I53. Retraction may be en'ected by mounting each blade-on springs which are compressed when the blade is pressed downwardly. The springs may be disposed beneath lugs I13, I13 on opposite sides of each blade. When the blades have been raised high enough to clear the die member, the die member Iau is indexed to the leit a distance corresponuing to three iorming cavities. 'i'nus it is indexed suinciently so that ma or blade Ill is moved lertwaruiy to occupy the P05151011 which major blade Ice is shown to occupy in Fig. 19. when this has been done, major trough corrugation l'ul will lie directly beneath hold-down blade I54, and minor corrugation I12 will be directly beneath hold-down blade I55. he device is then ready tor a repetition oi the steps described above to rorm tnree more corrugations by depressing blades I56, I51 and I58 in sequence. Any convcment means may be used to synchronize the indexing action with the rotation or the cams, as will be understood Iroin the foregoing discussion 01' Figs. 6-18.

It will be recognized that the device of Fig.

19 embodies each of the basic principles involved in the device of Figs. 6-18. It should be especially noted that the three forming biades are not depressed simultaneously. If this were done, the unformed strip stock would not be pulled into each of the iorming cavities in succession but rather would be clamped by the forming blade and subjected to a drawing operation which would break such relatively mextensible stock as the device is designed to accommodate. On the contrary, by depressing the three blades in sequence, the inextensible stock is drawn freely into each consecutive cavity to form one corrugation at a time, and

consequently is not subjected to stresses which would cause it to break. This feature will, of course, be thoroughly understood from the discussion of Figs. 6-18.

The modification shown in Figs. 23 and 24 involves the substitution of a conical rotating die member 114 201 the annular rotating die member G to Figs. 6-18. A single pivoted forming blade I15 is connected to punch holder I16 mounted in the slide of a punch press for use in combination with the conical die member. Its construction and operation is similar to that of pivoted forming blade III of Figs. 6, '1 and 8. The strip stock 111 is fed through a guide I18 which delivers it to a desire dposition. on the fixed forming blades I19 and I of the conical die member. The pivotal forming blade I15 re- ,54 of Figs. 7 and 9. A stripping plate I85 may be disposed adjacent the periphery of the conical die member to peel the corrugated .stock away from the conical die member as the latter rotates intermittently. It will, of course, be recognized that the intermittently rotating die member I14 is indexed clockwise (as viewed in Fig. 23) for a distance of one forming cavity at a. time after each complete stroke of the forming blade. This synchronized indexing action duplicates that of the device of Figs. 6-18 and will therefore be fully understood without further explanation. Fig. 23 shows the die member indexed through half of its usual angular distance to show how it pulls the strip stock with it as it rotates.

Those skilled in the art will recognize that the modifications illustrated in Figs. 19-23 inclusive represent only a few of the numerous constructions which may be devised to utilize the principles of operation disclosed herein, since many machines may be constructed in which male and female die members are utilized to bend metal strip stock into rectilinear cor;- rugations of difierent depths by successive bending operations. Either the male or female die member may reciprocate relative to the other, and it is not necessary that either one have rotary or arcuate motion in the plane of the strip stock since those skilled in the. art will recognize that the metal stock may itself be suitably indexed relative to both die members so as to bring the successive transverse portions thereof into position to be bent into corrugations. .Where this principle is utilized, it is not necessary that the female die structure have fixed forming blades of different heights, since each forming blade may simulate the forming blade 9|, and'may'have its inclination changed periodically to constitute a high or major blade at a selected time period in the sequence of operations, and later to constitute a suitably inclined minor blade. Numerous other modifications may be utilized, and will be apparent-to those skilled in the art. In view thereof, the devices here illustrated should not be regarded in a limiting sense, all constructions, and equivalents thereof, which are embraced within the following claims being within the bounds of the invention.

What I claim is:

1. In apparatus for bending straight metallic strip stock to form, edgewis curving corrugated arcuate members, the combination of a substantially fiat, rotatably mounted female die structure having a circular series of groups of mutually converging upstanding blades, each group comprising a maior blade followed by two minor blades, said blades having rectilinear edges over which the strip stock is bent to form major and minor crest corrugations and having intervening spaces between said blades to re ceive trough corrugations of the strip stock, the rectilinear edges of the minor blades bein disposed lower than and inclined inwardly toward the plane of the rectilinear edges of the major blades; 3. male die structure comprising a forming 'blade having a rectilinear edge for forming trough corrugations in the strip stock; means for rotatably indexing the female die, structure in relation to the male die blade; means for reciprocating the male die blade into and out of successive spaces between the blades of the female die structure as the latter is rotatably indexed; and means for positioning the rectilinear edge of said male die blade parallel to said plane when it is reciprocated between two minor blades.

2. Apparatus as claimed in claim 1 in which the made die blade is pivotally carried by the male die structure, and the means for positioning the rectilinear edge of the male'die blade includes cam means for inclining said rectilinear edge of the male die blade when it is reciprocated between a major and minor blade.

SAMUEL K. WELIMAN. 

